Mandible behaviour interpretation during wakefulness, sleep and sleep-disordered breathing

The mandible movement (MM) signal provides information on mandible
activity. It can be read visually to assess sleep–wake state and
respiratory events. This study aimed to assess (1) the training of
independent scorers to recognize the signal specificities; (2) intrascorer
reproducibility and (3) interscorer variability. MM was collected in the
mid-sagittal plane of the face of 40 patients. The typical MM was
extracted and classified into seven distinct pattern classes: active
wakefulness (AW), quiet wakefulness or quiet sleep (QW/S), sleep
snoring (SS), sleep obstructive events (OAH), sleep mixed apnea (MA),
respiratory related arousal (RERA) and sleep central events (CAH). Four
scorers were trained; their diagnostic capacities were assessed on two
reading sessions. The intra- and interscorer agreements were assessed
using Cohen’s j. Intrascorer reproducibility for the two sessions ranged
from 0.68 [95% confidence interval (CI): 0.59–0.77] to 0.88 (95% CI:
0.82–0.94), while the between-scorer agreement amounted to 0.68 (95%
CI: 0.65–0.71) and 0.74 (95% CI: 0.72–0.77), respectively. The overall
accuracy of the scorers was 75.2% (range: 72.4–80.7%). CAH MMs
were the most difficult to discern (overall accuracy 65.6%). For the two
sessions, the recognition rate of abnormal respiratory events (OAH,
CAH, MA and RERA) was excellent: the interscorer mean agreement
was 90.7% (Cohen’s j: 0.83; 95% CI: 0.79–0.88). The discrimination of
OAH, CAH, MA characteristics was good, with an interscorer agreement
of 80.8% (Cohen’s j: 0.65; 95% CI: 0.62–0.68). Visual analysis of
isolated MMs can successfully diagnose sleep–wake state, normal and
abnormal respiration and recognize the presence of respiratory effort.